Abstract
Thawing Arctic permafrost causes massive fluvial and erosional releases of dissolved and particulate organic carbon (DOC and POC) to coastal waters. Here we investigate how different sources and degradation of remobilized terrestrial carbon may affect large-scale carbon cycling, by comparing molecular and dual-isotope composition of waterborne high molecular weight DOC (>1 kD, aka colloidal OC), POC, and sedimentary OC (SOC) across the East Siberian Arctic Shelves. Lignin phenol fingerprints demonstrate a longitudinal trend in relative contribution of terrestrial sources to coastal OC. Wax lipids and cutins were not detected in colloidal organic carbon (COC), in contrast to POC and SOC, suggesting that different terrestrial carbon pools partition into different aquatic carrier phases. The Δ14C signal suggests overwhelmingly contemporary sources for COC, while POC and SOC are dominated by old C from Ice Complex Deposit (ICD) permafrost. Monte Carlo source apportionment (δ13C, Δ14C) constrained that COC was dominated by terrestrial OC from topsoil permafrost (65%) and marine plankton (25%) with smaller contribution ICD and other older permafrost stocks (9%). This distribution is likely a result of inherent compositional matrix differences, possibly driven by organomineral associations. Modern OC found suspended in the surface water may be more exposed to degradation, in contrast to older OC that preferentially settles to the seafloor where it may be degraded on a longer timescale. The different sources which partition into DOC, POC, and SOC appear to have vastly different fates along the Eurasian Arctic coastal margin and may possibly respond on different timescales to climate change.
| Original language | English |
|---|---|
| Pages (from-to) | 898-919 |
| Number of pages | 22 |
| Journal | Global Biogeochemical Cycles |
| Volume | 30 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 1 Jun 2016 |
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Keywords
- biomarkers
- carbon isotopes
- coastal Arctic
- degradation state
- organic matter
- source apportionment
ASJC Scopus subject areas
- Global and Planetary Change
- Environmental Chemistry
- Environmental Science(all)
- Atmospheric Science
Cite this
Different sources and degradation state of dissolved, particulate, and sedimentary organic matter along the Eurasian Arctic coastal margin. / Karlsson, Emma; Gelting, Johan; Tesi, Tommaso; van Dongen, Bart; Andersson, August; Semiletov, Igor Petrovich; Charkin, Alexander; Dudarev, Oleg Victorovich; Gustafsson, Örjan.
In: Global Biogeochemical Cycles, Vol. 30, No. 6, 01.06.2016, p. 898-919.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Different sources and degradation state of dissolved, particulate, and sedimentary organic matter along the Eurasian Arctic coastal margin
AU - Karlsson, Emma
AU - Gelting, Johan
AU - Tesi, Tommaso
AU - van Dongen, Bart
AU - Andersson, August
AU - Semiletov, Igor Petrovich
AU - Charkin, Alexander
AU - Dudarev, Oleg Victorovich
AU - Gustafsson, Örjan
PY - 2016/6/1
Y1 - 2016/6/1
N2 - Thawing Arctic permafrost causes massive fluvial and erosional releases of dissolved and particulate organic carbon (DOC and POC) to coastal waters. Here we investigate how different sources and degradation of remobilized terrestrial carbon may affect large-scale carbon cycling, by comparing molecular and dual-isotope composition of waterborne high molecular weight DOC (>1 kD, aka colloidal OC), POC, and sedimentary OC (SOC) across the East Siberian Arctic Shelves. Lignin phenol fingerprints demonstrate a longitudinal trend in relative contribution of terrestrial sources to coastal OC. Wax lipids and cutins were not detected in colloidal organic carbon (COC), in contrast to POC and SOC, suggesting that different terrestrial carbon pools partition into different aquatic carrier phases. The Δ14C signal suggests overwhelmingly contemporary sources for COC, while POC and SOC are dominated by old C from Ice Complex Deposit (ICD) permafrost. Monte Carlo source apportionment (δ13C, Δ14C) constrained that COC was dominated by terrestrial OC from topsoil permafrost (65%) and marine plankton (25%) with smaller contribution ICD and other older permafrost stocks (9%). This distribution is likely a result of inherent compositional matrix differences, possibly driven by organomineral associations. Modern OC found suspended in the surface water may be more exposed to degradation, in contrast to older OC that preferentially settles to the seafloor where it may be degraded on a longer timescale. The different sources which partition into DOC, POC, and SOC appear to have vastly different fates along the Eurasian Arctic coastal margin and may possibly respond on different timescales to climate change.
AB - Thawing Arctic permafrost causes massive fluvial and erosional releases of dissolved and particulate organic carbon (DOC and POC) to coastal waters. Here we investigate how different sources and degradation of remobilized terrestrial carbon may affect large-scale carbon cycling, by comparing molecular and dual-isotope composition of waterborne high molecular weight DOC (>1 kD, aka colloidal OC), POC, and sedimentary OC (SOC) across the East Siberian Arctic Shelves. Lignin phenol fingerprints demonstrate a longitudinal trend in relative contribution of terrestrial sources to coastal OC. Wax lipids and cutins were not detected in colloidal organic carbon (COC), in contrast to POC and SOC, suggesting that different terrestrial carbon pools partition into different aquatic carrier phases. The Δ14C signal suggests overwhelmingly contemporary sources for COC, while POC and SOC are dominated by old C from Ice Complex Deposit (ICD) permafrost. Monte Carlo source apportionment (δ13C, Δ14C) constrained that COC was dominated by terrestrial OC from topsoil permafrost (65%) and marine plankton (25%) with smaller contribution ICD and other older permafrost stocks (9%). This distribution is likely a result of inherent compositional matrix differences, possibly driven by organomineral associations. Modern OC found suspended in the surface water may be more exposed to degradation, in contrast to older OC that preferentially settles to the seafloor where it may be degraded on a longer timescale. The different sources which partition into DOC, POC, and SOC appear to have vastly different fates along the Eurasian Arctic coastal margin and may possibly respond on different timescales to climate change.
KW - biomarkers
KW - carbon isotopes
KW - coastal Arctic
KW - degradation state
KW - organic matter
KW - source apportionment
UR - http://www.scopus.com/inward/record.url?scp=84978420784&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84978420784&partnerID=8YFLogxK
U2 - 10.1002/2015GB005307
DO - 10.1002/2015GB005307
M3 - Article
AN - SCOPUS:84978420784
VL - 30
SP - 898
EP - 919
JO - Global Biogeochemical Cycles
JF - Global Biogeochemical Cycles
SN - 0886-6236
IS - 6
ER -